A stainless steel-based composite material for brazing has been used as a bonding material in automotive oil coolers. In this material, copper as a brazing filler metal is clad on one side or both sides of a stainless steel plate.
Patent literature 1 has described a composite material for brazing and a brazing filler material having high corrosion resistivity and heat resistivity. These composite materials have such a structure that a nickel-chromium alloy, which includes 1 mass-percent to 30 mass-percent of chromium, is firstly laminated as a Fe-atom diffusion constraint layer on a base material consist of corrosion resistant steel, and then thereon copper brazing filler is laminated.
Patent Literature 1:
Japanese Unexamined Patent Publication: JP 2003-145290
Patent Literature 2:
Japanese Unexamined Patent Publication: JP 2004-291078